Anatomy of the Skin

Facts about the skin

The skin is the body's largest organ, covering the entire body. In addition to serving as a protective shield against heat, light, injury, and infection, the skin also:

Regulates body temperature

Stores water and fat

Is a sensory organ

Prevents water loss

Prevents entry of bacteria

Throughout the body, the skin's characteristics vary (for example, thickness, color, and texture). For instance, the head contains more hair follicles than anywhere else, while the soles of the feet contain none. In addition, the soles of the feet and the palms of the hands are much thicker than skin on other areas of the body.

The skin is made up of the following layers, with each layer performing specific functions:

Epidermis

Dermis

Subcutaneous fat layer

Epidermis

The epidermis is the thin outer layer of the skin that consists of three types of cells:

Squamous cells. The outermost layer is continuously shed.

Basal cells. Basal cells are found just under the squamous cells.

Melanocytes. Melanocytes are found in every layer of the epidermis and make melanin, which gives the skin its color.

Dermis

The dermis is the middle layer of the skin. The dermis contains the following:

Blood vessels

Lymph vessels

Hair follicles

Sweat glands

Collagen bundles

Fibroblasts

Nerves

The dermis is held together by a protein called collagen, which is made by fibroblasts. This layer gives skin flexibility and strength. It also contains pain and touch receptors.

Subcutaneous fat layer

Thesubcutaneous fat layer is the deepest layer of skin and consists of a network of collagen and fat cells. It helps conserve the body's heat and protects the body from injury by acting as a shock absorber.